CN107706575B

CN107706575B - Coaxial connector

Info

Publication number: CN107706575B
Application number: CN201710686648.2A
Authority: CN
Inventors: 丸山昭広; 泽井隆志
Original assignee: Hirose Electric Co Ltd
Current assignee: Hirose Electric Co Ltd
Priority date: 2016-08-09
Filing date: 2017-08-08
Publication date: 2020-04-21
Anticipated expiration: 2037-08-08
Also published as: US10164384B2; US20180048101A1; JP2018026238A; CN107706575A; JP6588403B2; KR20180018309A; KR102054657B1

Abstract

A coaxial connector has a structure in which a center conductor is bent into a substantially L-shape, and the impedance matching between the coaxial connector and a circuit or the like can be improved. In a coaxial connector (1) mounted on a substrate (2), a center conductor (31) includes: a contact portion (32) which is in contact with a terminal of a counterpart connector; a first connecting portion (33) which is connected to the contact portion and extends in the axial direction of the outer conductor (11); a bent portion (34) connected to the first connection portion and bent in the radial direction of the outer conductor; a second connection section (35) connected to the bent section and extending in the radial direction of the outer conductor; and a connecting portion (36) connected to the second connecting portion and connecting the center conductor to the circuit of the substrate, wherein the first connecting portion is formed with a first protruding portion (41) formed by protruding a part of the outer peripheral surface of the first connecting portion, and the second connecting portion is formed with a second protruding portion (42) formed by protruding a part of the outer peripheral surface of the second connecting portion.

Description

Coaxial connector

Technical Field

The present invention relates to a coaxial connector mounted on a substrate.

Background

A coaxial connector of a type mounted on a substrate can be used as a member for connecting a circuit formed on the substrate and a device independent of the substrate by a coaxial cable. In the case where the signal processed by the above-described circuit and apparatus is a high-frequency signal, it is very important to integrate (match) the impedance of the coaxial connector with the input impedance or the output impedance of the circuit.

The impedance of the coaxial connector varies depending on the structural elements of the coaxial connector, such as the shape and size of the center conductor and the outer conductor, and the distance between the center conductor and the outer conductor. When designing a coaxial connector, these structural elements are appropriately adjusted to match the impedance of the coaxial connector with the input impedance of the circuit.

Patent document 1 listed below describes an example of adjusting the impedance of a coaxial connector by adjusting structural elements of the coaxial connector.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2015-95326

Disclosure of Invention

Technical problem to be solved by the invention

However, among the types of coaxial connectors mounted on a substrate are the following: the outer conductor is disposed on the substrate so that the axis thereof is perpendicular to the surface of the substrate, while the center conductor is formed in a substantially L-shape, and a portion of the center conductor that is in contact with the terminal of the mating connector is elongated in a direction perpendicular to the surface of the substrate, and a portion connected to the circuit of the substrate is elongated in a direction horizontal to the surface of the substrate. The coaxial connector described in patent document 1 also has the above-described structure. When processing high frequency signals, particularly high frequency signals in a quasi-millimeter wave band having a frequency of approximately 20GHz to 30GHz or a millimeter wave band having a frequency of approximately 30GHz or more, it is not easy for the coaxial connector having the above-described configuration to match the impedance of the coaxial connector with the input impedance of a circuit or the like.

The main reason for this is considered to be that the center conductor is L-shaped, which is more complicated in shape than a straight line, or that the distance between the center conductor and the outer conductor is greatly different depending on the portion of the center conductor because the center conductor is L-shaped. Another factor is that the frequency of the signal to be processed is very high. That is, when the signal to be processed is close to the quasi-millimeter wave band or the millimeter wave band, it becomes considerably difficult to control the impedance of the coaxial connector by adjusting the structural elements of the coaxial connector as compared with the band lower than the band of the signal.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a coaxial connector having a structure in which a center conductor is bent into a substantially L-shape, and which can improve impedance matching between the coaxial connector and a circuit or the like.

Technical scheme for solving technical problem

In order to solve the above-described problems, a coaxial connector according to the present invention includes a cylindrical outer conductor and a center conductor provided inside the outer conductor, the coaxial connector being mounted on a substrate, the center conductor including: a contact portion that contacts a terminal of a counterpart connector; a first connecting portion connected to the contact portion and elongated in an axial direction of the outer conductor; a bent portion connected to the first connection portion and bent in a radial direction of the outer conductor; a second connection portion connected to the bent portion and extending in a radial direction of the outer conductor; and a connection portion connected to the second connection portion and connecting the center conductor to a circuit of the substrate, wherein the first connection portion is formed with a first protruding portion formed by protruding a part of an outer peripheral surface of the first connection portion, and the second connection portion is formed with a second protruding portion formed by protruding a part of an outer peripheral surface of the second connection portion.

According to the coaxial connector of the present invention, the first projecting portion and the second projecting portion are provided on both sides of the bent portion of the center conductor, respectively, so that the impedance matching between the coaxial connector and a circuit or the like can be improved.

In the coaxial connector according to the present invention, the first projecting portion is preferably formed in a cylindrical shape having a diameter larger than that of the first connecting portion. Preferably, the second protruding portion is formed in a cylindrical shape having a diameter larger than that of the second coupling portion. Preferably, the first protruding portion is disposed coaxially with the first connecting portion. Preferably, the second protruding portion is disposed coaxially with the second coupling portion. Preferably, the second protruding portion is disposed inside the outer peripheral surface of the outer conductor.

In the coaxial connector according to the present invention, it is preferable that a conductor region is formed on a surface of the substrate in a portion corresponding to an end surface of the end portion of the external conductor on the side close to the substrate, a conductor pattern is laid on the conductor region, a non-conductor region is formed on a surface of the substrate in a portion corresponding to a space inside the end portion of the external conductor, the non-conductor region is not laid on the conductor pattern, and the second protruding portion is disposed above the non-conductor region.

In addition, the coaxial connector according to the present invention includes an insulating member that supports the center conductor with respect to the outer conductor, the insulating member including: an insertion hole through which the contact portion is inserted; an accommodating portion which is a hole having a diameter larger than that of the insertion hole and accommodates the first protruding portion; and a step portion formed between the insertion hole and the housing portion, the first protruding portion abutting against the step portion.

In the coaxial connector according to the present invention, the second coupling portion of the center conductor may be formed with an adjusting portion formed by locally changing a diameter dimension of the second coupling portion at a portion radially outward of the second protruding portion in the outer conductor.

Effects of the invention

According to the present invention, in the coaxial connector having the structure in which the center conductor is bent into the substantially L-shape, the impedance matching between the coaxial connector and the circuit or the like can be improved.

Drawings

Fig. 1 is an external view showing a substrate and a coaxial connector according to a first embodiment of the present invention before being mounted on the substrate.

Fig. 2 is an external view of the coaxial connector according to the first embodiment of the present invention, as viewed from the direction of arrow II in fig. 1.

Fig. 3 is a sectional view of the coaxial connector in the first embodiment of the present invention, as viewed in the direction of arrows III-III in fig. 2.

Fig. 4 is an exploded view of the coaxial connector according to the first embodiment of the present invention, as viewed from the upper side.

Fig. 5 is an exploded view of the coaxial connector according to the first embodiment of the present invention, as viewed from the lower side.

Fig. 6 is a perspective view showing a center conductor of a coaxial connector according to a first embodiment of the present invention.

Fig. 7 is an external view of the center conductor of the coaxial connector according to the first embodiment of the present invention, as viewed from the side.

Fig. 8 is an explanatory view showing a positional relationship between the first and second protruding portions of the center conductor and the outer conductor in the coaxial connector according to the first embodiment of the present invention, and is an explanatory view showing a positional relationship between the first and second protruding portions of the center conductor and the conductor pattern of the substrate.

Fig. 9 is an external view showing a center conductor of a coaxial connector of a comparative example.

Fig. 10 is a graph showing Voltage Standing Wave Ratios (VSWR) of the coaxial connectors according to the first embodiment of the present invention when a high-frequency signal flows from a signal source to the center conductor of the coaxial connector and flows to the center conductor of the coaxial connector according to the comparative example.

Fig. 11 is an external view showing a center conductor of a coaxial connector according to a second embodiment of the present invention.

Fig. 12 is a graph showing voltage standing wave ratios of the coaxial connectors when a high-frequency signal flows from a signal source to the center conductor of the coaxial connector according to the first embodiment of the present invention and when a high-frequency signal flows to the center conductor of the coaxial connector according to the second embodiment of the present invention.

Fig. 13 is an explanatory view showing the distribution of electric field vectors in the vicinity of the first extending portion formed in the center conductor in each of the coaxial connectors according to the first and second embodiments of the present invention.

Fig. 14 is an external view showing a center conductor of a coaxial connector according to a third embodiment of the present invention.

Fig. 15 is a graph showing voltage standing wave ratios of the coaxial connectors in the first embodiment of the present invention when a high-frequency signal flows from a signal source to the center conductor of the coaxial connector and in the third embodiment of the present invention to the center conductor of the coaxial connector.

Fig. 16 is an external view showing a center conductor of a coaxial connector according to a fourth embodiment of the present invention.

Fig. 17 is a graph showing voltage standing wave ratios of the coaxial connectors according to the fourth embodiment of the present invention when a high-frequency signal flows from a signal source to the center conductor of the coaxial connector according to the first embodiment of the present invention and flows to the center conductor of the coaxial connector according to the fourth embodiment of the present invention.

Fig. 18 is an external view showing a center conductor of a coaxial connector according to a fifth embodiment of the present invention.

(symbol description)

1a coaxial connector;

2a substrate;

3. 4 a conductor pattern;

5 a conductor region;

6 a non-conductor region;

11 an outer conductor;

11A outer peripheral surface;

21 an insulating member;

25 inserting through holes;

27 a housing part;

28 step part;

31. 51, 61, 71, 81 center conductors;

32. 52, 62, 72, 82 contact portions;

33. 53, 63, 73, 83 first connecting parts;

34. 54, 64, 74, 84 fold;

35. 55, 65, 75, 85 second connecting parts;

36. 56, 66, 76, 86 connections;

41. 57, 67, 77, 87 first extensions;

42. 58, 68, 78, 88 second extension;

89 an adjusting part.

Detailed Description

Fig. 1 shows a state before a coaxial connector 1 according to a first embodiment of the present invention is mounted on a substrate 2. Fig. 2 shows the coaxial connector 1 as seen from the direction of arrow II in fig. 1, and fig. 3 shows a cross section of the coaxial connector 1 as seen from the direction of arrows III-III in fig. 2. Fig. 4 is an exploded view of the coaxial connector 1 as viewed from the upper side, and fig. 5 is an exploded view of the coaxial connector 1 as viewed from the lower side. In the following description, for convenience of explanation, a case will be described as an example in which the substrate 2 is horizontally placed and the coaxial connector 1 is mounted on the upper surface of the substrate 2.

In fig. 1, a coaxial connector 1 is a type of coaxial connector mounted on a surface of a substrate 2. The coaxial connector 1 is mounted on the substrate 2 such that the axis thereof is perpendicular to the surface of the substrate 2. By inserting the mating connector into the coaxial connector 1 from above the substrate 2, electrical connection between the mating connector and a circuit formed on the substrate 2 can be performed. The coaxial connector 1 includes an outer conductor 11, a center conductor 31, and an insulating member 21, wherein the insulating member 21 supports the center conductor 31 to insulate the center conductor 31 from the outer conductor 11. On the other hand, the substrate 2 is, for example, a teflon (registered trademark) substrate or a ceramic substrate, the

conductor patterns

3 and 4 are formed on the front surface of the substrate 2, and the conductor film is formed on the entire back surface of the substrate 2. The

conductor patterns

3, 4 constitute a part of the circuit.

In the coaxial connector 1, the outer conductor 11 functions as a housing of the coaxial connector 1 and as an electrical connection member such as a ground. The outer conductor 11 also functions as a member for fixing the coaxial connector 1 to the substrate 2. The outer conductor 11 is formed into a cylindrical shape by cutting a metal bar such as brass or phosphor bronze. The outer conductor 11 may be formed by bending a metal plate material into a cylindrical shape, but the accuracy of the impedance of the coaxial connector 1 can be improved by forming the outer conductor 11 by cutting a metal bar material. The surface of the outer conductor 11 is plated with, for example, nickel, and is also plated with gold or tin in an overlapping manner. The size of the outer conductor 11 is not limited, and may be, for example, about 3mm to 10mm in diameter and about 4mm to 12mm in height.

As shown in fig. 2, a fitting portion 12 into which a mating connector is detachably fitted is formed at an upper portion of the outer conductor 11. As shown in fig. 3, a connector locking portion 13 is formed on the inner peripheral side of the fitting portion 12, and the connector locking portion 13 locks the mating connector inserted into the fitting portion 12. The connector locking portion 13 protrudes radially inward from the inner circumferential surface of the fitting portion 12 over the entire circumference.

A support portion 14 is formed on the inner peripheral side of the lower portion of the outer conductor 11, and the support portion 14 supports the center conductor 31 via the insulating member 21. As shown in fig. 5, the insulating member 21 is inserted into the support portion 14 from below the support portion 14. The support portion 14 includes an insertion portion 15 into which a trunk portion 22 of an insulating member 21 is inserted. As shown in fig. 3, the inner diameter of the insertion portion 15 is smaller than the inner diameter of the fitting portion 12. In addition, the support portion 14 includes a groove portion 16 into which one branch portion 23 of the insulating member 21 is inserted. The groove 16 is formed in the lower end surface of the outer conductor 11, and the groove 16 extends from the edge of the insertion portion 15 in the radial direction of the outer conductor 11 so as to penetrate between the edge of the insertion portion 15 and the outer peripheral surface of the fixing portion 18. Further, the support portion 14 includes a recess 17 into which the other branch portion 24 of the insulating member 21 is inserted. The recess 17 is formed in a portion of the lower end surface of the outer conductor 11 on the opposite side of the portion where the groove portion 16 is formed. The above shape of the support portion 14 is an example, and is not limited to this.

Further, a fixing portion 18 is formed on the outer peripheral side of the lower portion of the outer conductor 11, and the fixing portion 18 connects and fixes the outer conductor 11 to the conductor pattern 3 of the substrate 2 by solder. The fixing portion 18 is formed in a flange shape in which a lower end portion of the outer peripheral surface of the outer conductor 11 extends outward in the radial direction. As shown in fig. 5, when the outer conductor 11 is viewed from below, the fixing portion 18 is formed in a substantially square shape, and a recessed portion 19 indicating the circumferential direction of the coaxial connector 1 is formed in a part of the outer peripheral surface of the fixing portion 18. The above shape of the fixing portion 18 is an example, and is not limited thereto.

In the coaxial connector 1, the insulating member 21 is formed of an insulating material, for example, a resin such as a liquid crystal polymer. As shown in fig. 4, the insulating member 21 includes a cylindrical main portion 22 and a pair of

branch portions

23, 24, wherein the pair of

branch portions

23, 24 are formed on both sides of the main portion 22 in the radial direction and extend outward in the radial direction. As shown in fig. 3, an insertion hole 25 through which the contact portion 32 of the center conductor 31 is inserted is formed in an upper portion of the central portion of the trunk portion 22. In addition, a groove-shaped locking portion 26 for locking the center conductor 31 to the insulating member 21 is formed on the inner surface of the insertion hole 25. In addition, a receiving portion 27, which is a hole for receiving the first connecting portion 33, the first extending portion 41, and the bent portion 34 of the central conductor 31, is formed in a lower portion of the central portion of the trunk portion 22. The receiving portion 27 has a diameter larger than that of the insertion hole 25, and a step portion 28 is formed between the insertion hole 25 and the receiving portion 27. The first projecting portion 41 abuts on the step portion 28. Further, a space is formed between the bent portion 34 and the insulating member 21 in the housing portion 27. Since the bent portion 34 is not in contact with the insulating member 21 and air is interposed therebetween, the insertion loss of the coaxial connector 1 can be reduced. The narrow groove 29 is formed in the lower end surface of the branch portion 23 of the insulating member 21 so as to penetrate in the radial direction. The second coupling portion 35 and the second protruding portion 42 of the center conductor 31 are inserted into the narrow groove 29. The above shape of the insulating member 21 is an example, and is not limited thereto.

Fig. 6 and 7 show the center conductor 31 of the coaxial connector 1. That is, fig. 6 is a view of the central conductor 31 as viewed from the upper side, and fig. 7 is a view of the central conductor 31 as viewed from the side. As shown in fig. 6, the center conductor 31 is a terminal for transmitting signals, and the center conductor 31 is formed into an L-shaped bar shape by cutting and bending a metal bar such as brass, phosphor bronze, or the like, plating nickel on the surface thereof, and then plating gold or tin on the surface thereof in an overlapping manner.

The central conductor 31 includes a contact portion 32, a first connecting portion 33, a bent portion 34, a second connecting portion 35, and a connecting portion 36. That is, as shown in fig. 7, the center conductor 31 has a contact portion 32 formed on one end thereof to be in contact with a terminal of a mating connector. In the present embodiment, the contact portion 32 is male, and is formed in a pin shape. The other end of the contact portion 32 is connected to a first connecting portion 33, and the first connecting portion 33 linearly extends in the axial direction of the outer conductor 11. The other end of the first connecting portion 33 is connected to a bent portion 34, and the bent portion 34 is bent 90 degrees in the radial direction of the outer conductor 11. The other end of the bent portion 34 is connected to a second coupling portion 35, and the second coupling portion 35 linearly extends in the radial direction of the outer conductor 11. A connection portion 36 is formed on the other end side of the second connection portion 35, and the connection portion 36 connects the central conductor 31 to the circuit of the substrate. The contact portion 32, the first connecting portion 33, the bent portion 34, the second connecting portion 35, and the connecting portion 36 have a circular cross-sectional shape, and have a diameter of, for example, about 0.2 to 0.8 mm. The length L1 from the tip of the contact portion 32 to the bent portion 34 is, for example, about 4 to 12 mm. The length L2 from the bent portion 34 to the tip of the connecting portion 36 is, for example, about 3 to 12 mm. In addition, the first connecting portion 33 is formed with a flange-shaped locking portion 37, and the flange-shaped locking portion 37 is used for locking the center conductor 31 to the insulating member 21. The flange-shaped locking portion 37 is press-fitted and engaged with the groove-shaped locking portion 26 of the insulating member 21. Further, the connection portion 36 on the other end side of the center conductor 31 or a part of the connection portion 36 may be subjected to press working, cutting working, or the like, thereby forming a flat surface at least in a lower portion of the connection portion 36.

As shown in fig. 6, the first connecting portion 33 of the center conductor 31 has a first protruding portion 41 formed thereon. The first projecting portion 41 is formed below the flange-shaped locking portion 37. That is, a part of the outer peripheral surface of the first coupling portion 33 located below the flange-shaped locking portion 37 extends in the radial direction of the first coupling portion 33. This portion is the first extension 41. The first extending portion 41 is formed in a cylindrical shape, and the diameter of the cylindrical first extending portion 41 is larger than the diameter of any one of the first connecting portion 33 and the bent portion 34. The first extension 41 is disposed coaxially with the first connecting portion 33. The first projecting portion 41 projects sharply from the outer peripheral surface of the first connecting portion 33, and the first projecting portion 41 has an end surface 41A perpendicular to the outer peripheral surface of the first connecting portion 33.

In addition, as shown in fig. 3, the upper end surface 41A of the first projecting portion 41 abuts on the step portion 28 of the insulating member 21, whereby the position of the center conductor 31 is determined in the up-down direction with respect to the insulating member 21. That is, when the coaxial connector 1 is assembled, when the center conductor 31 is inserted into the insulating member 21, the position of the center conductor 31 in the insertion direction with respect to the insulating member 21 is determined as a designed position by the upper end surface 41A of the first projecting portion 41 coming into contact with the step portion 28. This prevents the center conductor 31 from entering in the insertion direction deeper than the designed position, and the second coupling portion 35 of the center conductor 31 collides strongly with the narrow groove 29 of the insulating member 21 to apply a large force to the second coupling portion 35, thereby deforming the second coupling portion 35.

As shown in fig. 6, a second protruding portion 42 is formed on the second connection portion 35 of the center conductor 31. That is, a portion of the outer peripheral surface of the second coupling portion 35 on the side closer to the center of the outer conductor 11 protrudes in the radial direction of the second coupling portion 35. This portion is the second projection 42. The second projecting portion 42 is formed in a cylindrical shape, the diameter of the cylindrical second projecting portion 42 is larger than the diameter of either the second coupling portion 35 or the bent portion 34, and the second projecting portion 42 is disposed coaxially with the second coupling portion 35. The second protruding portion 42 has an end face 42A perpendicular to the outer peripheral surface of the second coupling portion 35.

The first extending portion 41 and the second extending portion 42 are disposed on both sides of the bent portion 34. The first extending portion 41 and the second extending portion 42 are spaced apart from each other with the bent portion 34 interposed therebetween, but they are close to each other. In the present embodiment, the first extending portion 41 is located at the lower portion of the first connecting portion 33 in fig. 7, and a part of the first extending portion 41 reaches the upper portion of the bent portion 34. The second extending portion 42 is located on the right of the second coupling portion 35 in fig. 7, and a part of the second extending portion 42 reaches the left of the bent portion 34. As a result, the positions where the first extending portion 41 and the second extending portion 42 are formed are included in the range of the arc described by the bent portion 34. In the present embodiment, the diameter, volume, or area of the outer peripheral surface of the first projecting portion 41 is larger than the diameter, volume, or area of the outer peripheral surface of the second projecting portion 42.

Fig. 8 shows the positional relationship of the first protruding portion 41 and the second protruding portion 42 with the external conductor 11, and fig. 8 also shows the positional relationship of the first protruding portion 41 and the second protruding portion 42 with the conductor pattern 3 of the surface of the substrate 2. As shown in fig. 8, when the coaxial connector 1 according to the present embodiment is viewed from above, the first projecting portion 41 is disposed at the center of the outer conductor 11, and the entire second projecting portion 42 is disposed inside the outer peripheral surface 11A of the outer conductor 11. When the coaxial connector 1 is viewed from above, the second extending portion 42 is disposed inside the insertion portion 15, and the insertion portion 15 corresponds to the inner peripheral surface of the support portion 14 of the outer conductor 11. When the coaxial connector 1 is viewed from above, the second projecting portion 42 partially overlaps the first projecting portion 41.

In addition, the first projecting portion 41 and the second projecting portion 42 have the following positional relationship with the conductor pattern 3 formed on the surface of the substrate 2. That is, as shown in fig. 8, a conductive region 5 is formed on the surface of the substrate 2 at a portion corresponding to an end surface of the end portion of the external conductor 11 on the side close to the substrate 2, the conductive pattern 3 is laid on the conductive region 5, and a non-conductive region 6 where no conductive pattern is laid is formed on the surface of the substrate 2 at a portion corresponding to a space inside the end portion of the external conductor 11. The first extending portion 41 and the second extending portion 42 are disposed entirely above the non-conductor region 6.

The first projecting portion 41 and the second projecting portion 42 are formed integrally with the center conductor 31. That is, these projections are formed as a part of the central conductor 31 when the central conductor 31 is formed by cutting a metal bar.

Thus, by forming the first projecting portion 41 and the second projecting portion 42 on both sides of the bent portion 34 of the L-shaped center conductor 31, the impedance of the coaxial connector 1 and the input impedance, the output impedance, or the like of the circuit formed on the substrate 2 can be improved in conformity even when a high-frequency signal, particularly a high-frequency signal of a quasi millimeter wave band or a millimeter wave band, flows in the center conductor 31.

Here, the impedance matching of the coaxial connector 1 is specifically studied. First, a first study was conducted using fig. 9 and 10. Fig. 9 shows a center conductor 101 of the coaxial connector of the first comparative example, a center conductor 102 of the coaxial connector of the second comparative example, and a center conductor 103 of the coaxial connector of the third comparative example, respectively. The

central conductors

101, 102, and 103 are each formed in an L-shaped rod shape, and the rod-shaped

central conductors

101, 102, and 103 each have a contact portion 104, a first connecting portion 105, a bent portion 106, a second connecting portion 107, and a connecting portion 108. These points are the same as the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. However, the central conductor 101 is not formed with the protruding portion corresponding to the first protruding portion 41 of the central conductor 31 and the protruding portion corresponding to the second protruding portion 42 of the central conductor 31. The central conductor 102 has the extension 109 corresponding to the first extension 41 of the central conductor 31, but has no extension corresponding to the second extension 42 of the central conductor 31. In addition, although the central conductor 103 is formed with the protruding portion 110 corresponding to the second protruding portion 42 of the central conductor 31, it is not formed with the protruding portion corresponding to the first protruding portion 41 of the central conductor 31.

In the graph of fig. 10, a solid line indicates a Voltage Standing Wave Ratio (VSWR) on the coaxial connector side when a high-frequency signal flows from a signal source to the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. The two-dot chain line indicates the voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from the signal source to the center conductor 101 of the coaxial connector of the first comparative example. The dashed-dotted line indicates the voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from the signal source to the center conductor 102 of the coaxial connector of the second comparative example. The broken line indicates the voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from the signal source to the center conductor 103 of the coaxial connector of the third comparative example. According to fig. 10, the coaxial connector 1 according to the first embodiment of the present invention has a voltage standing wave ratio of approximately 1 in almost all frequency bands from dc to 10GHz and a voltage standing wave ratio of approximately 1 in all frequency bands from 10GHz to 40GHz, as compared with any of the coaxial connectors according to the comparative examples. From this, it is understood that by forming the first projecting portion 41 and the second projecting portion 42 on both sides of the bent portion 34 of the center conductor 31, it is possible to improve the matching of the impedance between the coaxial connector and the substrate circuit and the like in a frequency band smaller than the quasi-millimeter wave frequency band, and to improve the matching of the impedance between the coaxial connector and the substrate circuit and the like in the quasi-millimeter wave frequency band and the millimeter wave frequency band (particularly, reliably and remarkably in the quasi-millimeter wave frequency band and the millimeter wave frequency band).

Next, a second study was performed using fig. 11, 12, and 13. Fig. 11 shows a center conductor 51 of a coaxial connector according to a second embodiment of the present invention. The central conductor 51 is formed in an L-shaped bar shape, the bar-shaped central conductor 51 includes a contact portion 52, a first connecting portion 53, a bent portion 54, a second connecting portion 55, and a connecting portion 56, the first connecting portion 53 is formed with a first protruding portion 57, and the second connecting portion 55 is formed with a second protruding portion 58. These points are the same as the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. However, unlike the central conductor 31, the first protruding portion 57 and the second protruding portion 58 of the central conductor 51 have a quadrangular prism shape.

In the graph of fig. 12, a solid line indicates a voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from a signal source to the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. The two-dot chain line indicates the voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from the signal source to the center conductor 51 of the coaxial connector according to the second embodiment of the present invention. According to fig. 12, the coaxial connector 1 according to the first embodiment of the present invention has a voltage standing wave ratio closer to 1 in the frequency band of 5GHz to 40GHz than the coaxial connector 1 according to the second embodiment of the present invention. It is understood that, in comparison with the case where the quadrangular prism-shaped protruding portion is formed on the center conductor, the cylindrical protruding portion is formed on the center conductor, and the impedance matching between the coaxial connector and the substrate circuit in the high frequency band, the quasi-millimeter wave band, and the millimeter wave band, which are smaller than the millimeter wave band, can be improved.

Fig. 13(1) shows the electric field vector distribution in the vicinity of the first extension 41 in the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. Fig. 13(2) shows the electric field vector distribution in the vicinity of the first extension portion 57 in the center conductor 51 of the coaxial connector according to the second embodiment of the present invention. As shown in fig. 13(1), the electric field vector distribution in the vicinity of the first extension 41 according to the first embodiment of the present invention is a distribution of almost ideal coaxial mode. On the other hand, as shown in fig. 13(2), the electric field vector distribution in the vicinity of the first extension portion 57 according to the second embodiment of the present invention is disturbed in the vector direction. One of the main causes of the disturbance in the vector direction as shown in fig. 13(2) is considered to be that the impedance matching of the coaxial connector according to the second embodiment of the present invention is inferior to the impedance matching of the coaxial connector 1 according to the first embodiment of the present invention.

Of course, the voltage standing wave ratio of the coaxial connector according to the second embodiment of the present invention shown in fig. 12 is closer to 1 than the voltage standing wave ratio of the coaxial connector according to each comparative example shown in fig. 10 in the frequency band of 30GHz to 40 GHz. As described above, the coaxial connector according to the second embodiment of the present invention can improve the matching of impedance between the coaxial connector and the substrate circuit in the millimeter wave band.

Next, a third study was performed using fig. 14 and 15. Fig. 14 shows a center conductor 61 of a coaxial connector according to a third embodiment of the present invention. The central conductor 61 is formed in an L-shaped bar shape, the bar-shaped central conductor 61 includes a contact portion 62, a first connecting portion 63, a bent portion 64, a second connecting portion 65, and a connecting portion 66, the first connecting portion 63 is formed with a first protruding portion 67, and the second connecting portion 65 is formed with a second protruding portion 68. These points are the same as the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. However, unlike the center conductor 31, the first extending portion 67 and the first connecting portion 63 of the center conductor 61 are not coaxially arranged, and the second extending portion 68 and the second connecting portion 65 of the center conductor 61 are not coaxially arranged.

In the graph of fig. 15, a solid line indicates a voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from a signal source to the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. The two-dot chain line indicates the voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from the signal source to the center conductor 61 of the coaxial connector according to the third embodiment of the present invention. According to fig. 15, the coaxial connector 1 according to the first embodiment of the present invention has a voltage standing wave ratio closer to 1 in the frequency band of 5GHz to 30GHz than that of the coaxial connector according to the third embodiment of the present invention. It is thus understood that the coaxial arrangement of the extension portion on the center conductor can improve the impedance matching between the coaxial connector and the substrate circuit in the high frequency band smaller than the quasi-millimeter wave band and the quasi-millimeter wave band.

Of course, the voltage standing wave ratio of the coaxial connector according to the third embodiment of the present invention shown in fig. 15 is closer to 1 than the voltage standing wave ratio of the coaxial connector according to each comparative example shown in fig. 10 in the frequency band of 15GHz to 40 GHz. As described above, the coaxial connector according to the third embodiment of the present invention can improve the impedance matching between the coaxial connector and the substrate circuit in the substantially quasi-millimeter wave band and the millimeter wave band.

Next, a fourth study was performed using fig. 16 and 17. Fig. 16 shows a center conductor 71 of a coaxial connector according to a fourth embodiment of the present invention. The central conductor 71 is formed in an L-shaped bar shape, the bar-shaped central conductor 71 includes a contact portion 72, a first connecting portion 73, a bent portion 74, a second connecting portion 75, and a connecting portion 76, the first connecting portion 73 is formed with a first protruding portion 77, and the second connecting portion 75 is formed with a second protruding portion 78. These points are the same as the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. However, the first projecting portion 77 of the center conductor 71 is located, for example, about 0.15mm above the first projecting portion 41 of the center conductor 31, and the second projecting portion 78 of the center conductor 71 is located, for example, about 0.5mm outside the second projecting portion 42 of the center conductor 31 in the radial direction of the outer conductor. That is, the distance between the first projecting portion 77 and the bent portion 74 of the center conductor 71 is larger than the distance between the first projecting portion 41 and the bent portion 34 of the center conductor 31, and the distance between the second projecting portion 78 and the bent portion 74 of the center conductor 71 is larger than the distance between the second projecting portion 42 and the bent portion 34 of the center conductor 31. In other words, either or both of the position of the first extending portion 77 and the position of the second extending portion 78 deviate from the range of the arc described by the bent portion 74.

In the graph of fig. 17, a solid line indicates a voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from a signal source to the center conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. The two-dot chain line indicates the voltage standing wave ratio on the coaxial connector side when a high-frequency signal flows from the signal source to the center conductor 71 of the coaxial connector according to the fourth embodiment of the present invention. According to fig. 17, the coaxial connector 1 according to the first embodiment of the present invention has a voltage standing wave ratio closer to 1 in the frequency band of 5GHz to 40GHz than the coaxial connector according to the fourth embodiment of the present invention. It is thus understood that the first extending portion and the second extending portion are respectively brought close to the bent portion of the center conductor, and the impedance matching between the coaxial connector and the substrate circuit in the high frequency band, the quasi-millimeter wave band, and the millimeter wave band, which are smaller than the quasi-millimeter wave band, can be improved.

Of course, as compared with the voltage standing wave ratio of the coaxial connector of each comparative example shown in fig. 10, the voltage standing wave ratio of the coaxial connector according to the fourth embodiment of the present invention shown in fig. 17 is closer to 1 in the former than in the latter in almost all frequency bands of 10GHz to 30 GHz. As described above, the coaxial connector according to the fourth embodiment of the present invention can improve the impedance matching between the coaxial connector and the substrate circuit in the substantially quasi-millimeter wave band.

Fig. 18 shows a center conductor 81 of a coaxial connector according to a fifth embodiment of the present invention. The central conductor 81 includes a contact portion 82, a first connecting portion 83, a bent portion 84, a second connecting portion 85, a contact portion 86, a first protruding portion 87, and a second protruding portion 88, similarly to the central conductor 31 of the coaxial connector 1 according to the first embodiment of the present invention. In addition, in the center conductor 81, the second coupling portion 85 has an adjusting portion 89 formed at a portion radially outward of the second extending portion 88 in the outer conductor. The adjusting portion 89 is formed by locally increasing or decreasing the diameter dimension of the second coupling portion 85. The step is formed on the circumferential surface of the second coupling portion 85 by the adjusting portion 89, but the step formed on the circumferential surface of the second coupling portion 85 by the adjusting portion 89 is smaller than the step (protrusion) formed on the circumferential surface of the second coupling portion 85 by the second protrusion portion 88. The number of the portions of the adjusting portion 89 that increase the diameter of the second coupling portion 85 (or decrease the diameter) is not limited to one, and may be two or more. The impedance of the coaxial connector can be finely adjusted by the adjustment section 89. Further, by changing the diameter of the connection portion 86, the impedance of the coaxial connector can be finely adjusted.

The present invention can be modified as appropriate within a range not departing from the spirit or scope of the invention read from the claims and the entire specification, and a coaxial connector accompanying such modification is also included in the technical idea of the present invention.

Claims

1. A coaxial connector comprising a cylindrical outer conductor, a center conductor provided inside the outer conductor, and an insulating member supporting the center conductor to the outer conductor, the coaxial connector being mounted on a substrate, the outer conductor being arranged on the substrate so that an axis thereof is perpendicular to a surface of the substrate, the center conductor having a substantially L-shape, a portion of the center conductor which is in contact with a terminal of a mating connector extending in a perpendicular direction with respect to the surface of the substrate, and a portion which is connected to a circuit of the substrate extending in a horizontal direction with respect to the surface of the substrate,

the center conductor includes:

a contact portion that contacts a terminal of a counterpart connector;

a first connecting portion connected to the contact portion and elongated in an axial direction of the outer conductor;

a bent portion connected to the first connecting portion and bent in a radial direction of the outer conductor; and

a second coupling portion connected to the bent portion and elongated in the radial direction; and

a connection portion connected to the second connection portion and connecting the central conductor to a circuit of the substrate,

the first connecting part is provided with a first extending part formed by extending a part of the outer peripheral surface of the first connecting part,

a second protruding portion formed by protruding a part of an outer peripheral surface of the second coupling portion is formed on the second coupling portion,

the diameter of the first extending part is larger than that of the bending part,

a flange-shaped locking portion is formed on the first coupling portion between the first projecting portion and the contact portion,

the insulating member includes: an insertion hole through which the contact portion is inserted; and a receiving portion which is a hole having a diameter larger than that of the insertion hole,

the first connecting portion, the first extending portion and the bending portion are accommodated in the accommodating portion,

in the housing portion, a space is formed between the bent portion and the insulating member.

2. The coaxial connector of claim 1,

the first protruding portion is formed in a cylindrical shape having a diameter larger than that of the first coupling portion.

3. The coaxial connector of claim 1 or 2,

the second protruding portion is formed in a cylindrical shape having a diameter larger than that of the second coupling portion.

4. The coaxial connector of claim 1 or 2,

the first protruding portion is disposed coaxially with the first connecting portion.

5. The coaxial connector of claim 1 or 2,

the second protruding portion is arranged coaxially with the second coupling portion.

6. The coaxial connector of claim 1 or 2,

the second protruding portion is disposed at a position closer to the inside than the outer peripheral surface of the outer conductor.

7. The coaxial connector of claim 1 or 2,

a conductor region is formed on a surface of the substrate at a portion corresponding to an end surface of an end portion of the external conductor on a side close to the substrate, a conductor pattern is laid on the conductor region, a nonconductor region is formed on a surface of the substrate at a portion corresponding to a space inside the end portion of the external conductor, the nonconductor region is not laid with the conductor pattern, and the second protruding portion is disposed above the nonconductor region.

8. The coaxial connector of claim 1 or 2,

the insulating member includes a stepped portion formed between the insertion hole and the receiving portion,

the first protruding portion abuts against the step portion.

9. The coaxial connector of claim 1 or 2,

the second coupling portion of the center conductor is formed with an adjusting portion formed by locally changing a diameter dimension of the second coupling portion at a portion located radially outward of the second protruding portion in the outer conductor.

10. The coaxial connector of claim 1 or 2,

the second projecting portion partially overlaps with the first projecting portion when the coaxial connector is viewed from above.

11. The coaxial connector of claim 1 or 2,

the position where the first protruding portion and the second protruding portion are formed is included in the range of the arc described by the bent portion.